TC Watch / 熱帶氣旋 > Selected TC Review / 重要熱帶氣旋回顧 > 202122W (LIONROCK 獅子山) [Refresh 更新]

202122W (LIONROCK 獅子山) - Profile 檔案

(First draft issued on October 28, 2021, final version issued on January 2, 2022)
(初稿於 2021 年 10 月 28 日發出,最後版本於 2022 年 1 月 2 日上載)

Brief profile of LIONROCK | 獅子山小檔案:

JTWC number 聯合颱風警報中心 (JTWC) 號碼 22W
International number 國際編號 2117
Period of existence 生存時期^ 2021/10/07 14 HKT - 2021/10/10 20 HKT
Maximum 1-minute wind (JTWC) JTWC 一分鐘平均最高中心風速

40 knots 節 (Tropical Storm equivalent 相當於熱帶風暴級)

Minimum pressure (JTWC) JTWC 最低氣壓 991 hPa 百帕
Highest TC signal by HKO
香港天文台發出最高熱帶氣旋警告信號
8 (SE) (Gale or Storm Signal 烈風或暴風信號)
Closest point of approach by HKO
香港天文台所示之最接近距離
SW 500 km (real-time warning 實時報告) / 490 km (TC report 熱帶氣旋報告)
Time of closest approach by HKO
香港天文台所示之最接近時間
2021/10/09 00 HKT (real-time warning 實時報告) / 14 HKT (TC report 熱帶氣旋報告)
Lowest pressure recorded at HKO
香港天文台錄得的最低氣壓
1003.2 hPa 百帕 (2021/10/09 03:35 HKT)

^Refers to the period between the HK Observatory's first and last bulletins for the tropical cyclone (with at least tropical depression intensity). For storms formed/dissipated/transformed into an extratropical cyclone outside the area bounded by 7-36°N and 100-140°E, information from the JTWC will be used instead.
^即香港天文台為該熱帶氣旋 (熱帶低氣壓級或更高) 作出發佈的時期。至於在北緯 7 至 36 度、東經 100 至 140 度外形成/消散/轉化為溫帶氣旋的風暴,本網將參考聯合颱風警報中心的資料。

TC signals in Hong Kong* 香港曾經生效的熱帶氣旋警告*:

Signal
信號
Date and time
日期和時間
Distance from HK
與香港的距離
Predicted movement
預測移動趨勢
Max. 10-min winds
中心最高十分鐘平均風速
2021/10/08 (FRI) 04:40 HKT** SSW 660 km NNW slowly 65 km/h (35 knots, TS)
2021/10/09 (SAT) 06:40 HKT SW 560 km NW slowly 75 km/h (40 knots, TS)
2021/10/10 (SUN) 04:40 HKT WSW 610 km WNW at 15 km/h 65 km/h (35 knots, TS)
2021/10/10 (SUN) 12:40 HKT WSW 730 km W/WSW at 15 km/h 65 km/h (35 knots, TS)
2021/10/10 (SUN) 14:20 HKT WSW 750 km W/WSW at 15 km/h 65 km/h (35 knots, TS)

*Based on the information from real-time tropical cyclone warning bulletins.
*根據實時熱帶氣旋警報資料。

**The #3 Strong Wind Signal was issued to replace the Strong Monsoon Signal.
**此三號強風信號取代強烈季候風信號。

Percentile Ranks 百分等級:

Percentile rank among storms with #8 Signal (at compilation of this review)*:
發出八號信號之風暴中的百分等級 (編寫此回顧之時)*:

*This measures the relative wind strength in Hong Kong caused by this storm compared with others that share the same signal. 指標顯示此風暴相對於其他發出同樣信號的風暴為香港帶來之風力強度

For more information, please refer to Wind Speed Data for TCs that Have Affected Hong Kong. 更多資訊載於 影響香港氣旋之風速數據

  Overall:
總計:
28
  Moderately weak
中等偏弱
Component Ranks 分部等級
  Reference stations:
參考站:
23
  Moderately weak
中等偏弱
  Victoria Harbour:
維多利亞港:
34
  Moderately weak
中等偏弱
  Urban:
市區:
30
  Moderately weak
中等偏弱
  Offshore & high ground
離岸和高地:
23
  Moderately weak
中等偏弱

Cyclones that attained similar rating (with signal #8): KHANUN (2017), KAI-TAK (2012), KOMPASU (2004)
相近級別之熱帶氣旋 (八號信號):卡努 (2017)、啟德 (2012)、圓規 (2004)

IR imagery animation 紅外線雲圖動畫:

TC track from HKWW 本站的熱帶氣旋路徑圖:

TC Track

TC track from HKO 天文台的熱帶氣旋路徑圖:

TC Track

TC Track

TC track with signal information 附有熱帶氣旋警告信號資料的路徑圖:

(Track figure courtesy of Lorenzo. Data from HKO. 鳴謝 Lorenzo 提供路徑圖,資料取自天文台)

TC Track

Past HKWW Bulletins 本站發佈

Please click here for bulletins on this tropical cyclone. 請按這裡

Storm Development Overview 風暴發展概覽

Unless otherwise stated, all times below are in Hong Kong Standard Time (UTC+8)
除非特別註明,下文時間均為香港標準時間 (協調世界時加 8 小時)

Following the return of the Madden-Julian Oscillation to phase 5 in early October, there was increased cloudiness and convective activities in the South China Sea and western part of the tropical Pacific. Numerical models pointed towards the formation of a tropical cyclone in southern South China Sea; it was initially projected to move northwestwards towards central to western Guangdong coast.

The disturbance, then known as 92W, remained disorganized as it moved west-northwest in the South China Sea. On October 6, satellite images revealed a broad area of low pressure in the seas southeast of Hainan Island. The wind field analysis showed that 92W had the characteristics of a monsoon depression; in particular, its strongest winds were in the northern periphery, while winds were light in the loosely-defined central region.

The JTWC was the first to issue bulletins associated with 92W. A tropical cyclone formation alert was issued early on October 3, before the system crossed the Philippines. The alert was reissued on each of the next three days. The NMC upgraded 92W into a tropical depression at 8 am October 6, initially forecasting the storm to move west-northwest and make landfall in central Vietnam. Meanwhile, the JMA issued a gale warning at 8 am October 7. Both the JTWC and HKO upgraded 92W into tropical depression status in the afternoon of October 7, which the former assigning the storm number 22W.

At the time of formation, 22W was moving slowly due to the lack of an apparent steering force. There was considerable spread among numerical model forecasts, but it was generally believed that 22W would turn north and move towards Hainan Island due to a weak ridge near the Philippines at that time. Then, as the subtropical ridge in southern China strengthened, 22W would turn west and cross the Gulf of Tonkin.

22W continued to consolidate on October 7. The JMA upgraded it into a tropical storm at 2 am October 8, naming it LIONROCK. By that time, LIONROCK had developed sufficiently to bring its strongest winds to near its circulation centre. LIONROCK moved north at a slightly faster speed on October 8, and made landfall near Qionghai, Hainan near 11 pm that day.

LIONROCK moved erratically while on land. According to the hourly location fixes by the NMC, LIONROCK initially moved west, reaching central Hainan in the morning of October 9. It then turned north to north-northeast and edged closer to Haikou at the northern coast in the afternoon. As the subtropical ridge established in southern China, LIONROCK eventually turned west again, crossing Qionghai Strait and entering the Gulf of Tonkin that night. LIONROCK's intensity remained stable while crossing Hainan, but the storm was on a weakening trend as it crossed the Gulf with dwindling convective activities.

LIONROCK moved west-northwest and later turned west to west-southwest in the Gulf of Tonkin. It reached northern Vietnam near Haipong at around 5 pm October 10, and weakened into an area of low pressure shortly afterwards.

自 10 月初季內震盪返回第五相,南海及熱帶太平洋西部雲量及對流活動增多。數值模式估計南海將有熱帶氣旋形成,初時預計該氣旋將向西北移動,大致趨向廣東中至西部沿岸。

擾動 92W 進入南海後向西北偏西移動。10 月 6 日,衛星圖上可見海南島東南方有一廣闊低壓區,而風場分析顯示它有季風低壓的特徵,其最大風區位於北部邊緣,而中心較為鬆散,風勢微弱。

聯合颱風警報中心率先為 92W 作出發佈,該中心於 10 月 3 日、92W 橫過菲律賓之前對其發出熱帶氣旋形成警報。警報於其後三天每天重新發佈。中國中央氣象台於 6 日上午 8 時將 92W 升格為熱帶低氣壓,首佈預料風暴向西北偏西移動並於越南中部登陸。日本氣象廳則於 7 日上午 8 時發出烈風警告。聯合颱風警報中心及香港天文台均於 7 日下午升格 92W 為熱帶低氣壓,前者給予風暴編號 22W。

由於缺乏明顯駛流力場,22W 形成初時移動緩慢。數值模式的估算有明顯差異,但大致預測受當時位於菲律賓的一道弱高壓影響,22W 將轉北移並靠近海南島。此後,隨著副熱帶高壓脊於華南增強,22W 將會轉向偏西移動,橫過北部灣。

22W 於 10 月 7 日繼續整合,日本氣象廳於 8 日上午 2 時將其升格為熱帶風暴,命名為獅子山。此時,獅子山已有所發展,最大風區回歸至其環流中心附近。8 日獅子山以略快的速度北移,並於下午約 11 時登陸海南島瓊海市一帶。

獅子山於陸上的移動較為不規則。按照中央氣象台的每小時定位,風暴最初西移,至 10 月 9 日上午到達海南中部。它其後轉向北至東北偏北移動,於下午靠近位於北岸的海口市。至副熱帶高壓脊於華南建立,獅子山最終西轉,橫過瓊州海峽並於當晚進入北部灣。獅子山橫過海南島時強度大致維持,但風暴橫過北部灣時對流活動減少,風暴呈減弱之勢。

獅子山於北部灣先向西北偏西移動,其後向西至西南偏西移。它於 10 月 10 日下午約 5 時到達越南北部並於海防市附近登陸,不久後減弱為低壓區。

Weather in Hong Kong During Approach 風暴影響時香港天氣狀況

Link to relevant HKO weather report bulletins: 8/109/1010/10
香港天文台相關天氣報告連結8/109/1010/10

In Hong Kong, LIONROCK's rainbands brought record-breaking daily rainfall in the month of October, and led to some of the biggest controversies directed to the HK Observatory in recent years.

Prior to the formation of LIONROCK, the northeast monsoon was affecting the coastal areas of Guangdong. The Strong Monsoon Signal was issued at 3:35 am October 6 to remind the public that strong easterly winds may affect the territory. While the Signal was cancelled in the morning, it was reissued at 11:40 pm that day. It was rather windy on October 7; strong force winds were recorded in offshore waters and on high ground, reaching gale force occasionally in some locations. A sailing boat capsized near Po Toi Island in the afternoon [link to news article]; one man was trapped beneath the overturned boat and was later pronounced dead after being sent to the hospital. The other man on the boat was injured.

In the afternoon of October 7, the Observatory indicated that LIONROCK would move north and would be closer to the coast of Guangdong than previously expected. As a result, it would consider issuing the #3 Strong Wind Signal in the early morning of October 8 to replace the Strong Monsoon Signal.

The weather in Hong Kong deteriorated towards midnight October 8 as the rainbands associated with LIONROCK approached the territory. The Amber Rainstorm Warning was issued at 11:20 pm October 7. Since around 2 am October 8, rain was almost falling non-stop for much of the day. The Observatory issued the #3 Strong Wind Signal at 4:40 am when LIONROCK was about 660 km south-southwest of Hong Kong; this was the first time that the #1 Signal was skipped since the approach of tropical cyclone SINLAKU in 2020.

Due to the combined effect of LIONROCK and the northeast monsoon, winds remained strong in the morning of October 8 and nearly reached gale force at Cheung Chau and Green Island. Coupled with the persistent heavy rain, it made for a chaotic situation to commuters and students. The Landslip Warning was issued at 9:50 am while the Special Announcement on Flooding in the Northern New Territories was issued half an hour later. A more intense rainband approached Hong Kong near 11 am; the Rainstorm Warning was upgraded to Red at 11:20 am, and further to Black 25 minutes later. This marked the second time the Black Rainstorm Warning was issued in the month of October since records began, the first being five years ago under the influence of tropical cyclone SARIKA. During the hour between 10:45 and 11:45 am, up to 86 mm of rain was recorded in Wan Chai, 84 mm in Southern District, and 76 mm in Eastern District.

Following the passage of the most intense rainband, the Observatory downgraded the Rainstorm Warning to Red at 12:45 pm. It remained in force for 5 hours, before being replaced by the Amber Warning at 5:45 pm. It was at around this time that the rain over Hong Kong finally subsided, for the first time in more than half a day. The Amber Rainstorm Warning, together with the Special Announcement on Flooding in the Northern New Territories, were eventually cancelled at 7:25 pm.

During the heavy rain and strong winds in the morning of October 8, a large bamboo scaffolding at Broadwood Road in Happy Valley collapsed [link to news article], falling onto two vehicles passing by; the drivers sustained injuries. Contact to seven workers in the site was lost; five escaped to safety while a male and a female worker were rescued. The female worker was later found dead at the hospital.

Most parts of Hong Kong received more than 200 to 300 mm of rain on October 8. The 329.7 mm registered at the Observatory was a new record for the month of October, the eighth highest daily rainfall ever observed, and the highest daily rainfall since June 9, 1998.

On the other hand, the wind speeds over Hong Kong remained more or less the same throughout October 8. The Observatory said that the #3 Signal would remain in force during the night of October 8 and the morning of October 9. However, winds started to strengthen in the small hours of October 9, with sustained storm force winds recorded at Ngong Ping and gales recorded at Cheung Chau, Tai Mei Tuk, Tap Mun, Tate's Cairn and Waglan Island. Numerical models also suggested that winds would remain rather strong throughout most of October 9. Almost without prior indications of a possible signal change, the Observatory issued the Pre-No. 8 Special Announcement at 4:40 am, announcing that the #8 Signal would be issued by 6:40 am the latest. Since Macau also gave an early warning of the pending signal upgrade at 3 am, it was believed that this might have influenced the HK Observatory's decision.

The #8 Southeast Gale or Storm Signal was issued after the 2-hour warning period. LIONROCK was situated in central Hainan at that time, around 560 km southwest of Hong Kong. Initially, the Observatory suggested that the #8 Signal would remain in force for some time that morning. Ironically, because rain was generally light in the morning of October 9, the weather was not as bad as the day before, when the #3 Signal was in force. At around 9 am, the Observatory said it would consider issuing the #3 Signal in the early afternoon. The expected time of signal change was postponed several times during the day (link to a table below), as winds failed to moderate and the weather actually became worse in the afternoon as another rainband arrived. The Amber Rainstorm Warning was issued at 1 pm, and several stations saw the highest wind speeds recorded during LIONROCK's passage. This included two reference stations: the gale force winds of 63 km/h recorded at Chek Lap Kok and the storm force winds of 94 km/h recorded at Cheung Chau. Sustained winds at Ngong Ping, an elevated location, reached hurricane force at 126 km/h, gusting to 154 km/h.

Shortly after sunset, the Observatory indicated that the #8 would remain in force before midnight. Places such as Lau Fau Shan, Peng Chau, Kowloon Star Ferry, Tai Po Kau and Tap Mun recorded stronger winds at night than in the afternoon. The Amber Rainstorm Warning in force during the afternoon was cancelled at 9:05 pm. The rain on October 9 was in general not as heavy as that on October 8. However, more than 100 mm of rain was still recorded over most of Hong Kong, with 130.3 mm recorded at the Observatory.

As LIONROCK started to move west in the night of October 9, winds in Hong Kong started to moderate in the small hours of October 10. The Observatory indicated that it would consider issuing the #3 Strong Wind Signal before sunrise. That signal was eventually issued at 4:40 am, when LIONROCK was 610 km west-southwest of Hong Kong. At 490 km from Hong Kong at its closest point of approach, LIONROCK was the farthest tropical cyclone to necessitate the #8 Signal since 1961. The 22-hour period of the #8 Signal also marked the longest for the southeast direction, surpassing the 21 hours and 45 minutes for tropical cyclone Agnes in 1978. It was however still far from the record of 35 hour and 35 minutes for a single direction of the Gale or Storm Signal (northeast), held by tropical cyclone Mary in 1960.

LIONROCK's rainbands moved west as the storm moved in the same general direction. By sunrise on October 10, rain was limited to the western part of Hong Kong. The Landslip Warning was cancelled at 10 am. Local wind speeds continued to decrease in the morning, and the #3 Signal was replaced by the #1 Standby Signal at 12:40 pm. The #1 Signal was short-lived as it was cancelled at 2:20 pm. LIONROCK was about to reach the 800-km boundary from Hong Kong at that time. The overall rainfall for October 10 was much less than that of October 9, although more than 50 mm was recorded in most of Hong Kong Island and parts of Lantau.

The weather improved gradually on October 10. As the dry northeast monsoon strengthened on October 11, the weather was generally fine that day, before it worsened again as tropical cyclone KOMPASU approached on October 12 and 13. As of 4 am October 10, 179 cases of fallen trees were reported to the government. There were 6 reports of flooding and 3 landslide cases. 14 people sought medical treatment at the Accident and Emergency Department of public hospitals due to injuries related to LIONROCK.

LIONROCK was a rather unusual tropical cyclone that led to strong winds and heavy rain even at a large distance and after making landfall at Hainan. The HK Observatory was criticized by the public for:

The Observatory also received widespread criticism as Assistant Director Sandy Song Man-kuen responded to a media question on whether they had misjudged the situation in the morning of October 8, saying that extreme weather events would become more frequent and urging the public to reduce carbon emission.

For these issues, Director Cheng Cho-ming of the Observatory explained their actions in a press conference on October 11 [links to news articles: 1 2]:

Cheng mentioned that LIONROCK was a special case rarely seen in the last several decades, and expressed sadness on the lives lost during bad weather conditions. As for the press conference attended by Sandy Song, Cheng said that the response was meant to address the theme of that conference, with carbon emissions reduced to zero by the year 2050.

Time Description
October 9
06:49 The (#8 Signal) is expected to remain in force for some time this morning
08:47 The Observatory will consider issuing the (#3 Signal) ... in the early part of the afternoon
10:47 The Observatory will consider issuing the (#3 Signal) ... in the afternoon
12:45 The Observatory will consider issuing the (#3 Signal) ... in the afternoon to the evening
13:45 The Observatory will consider issuing the (#3 Signal) ... around the evening
15:45 When the local winds show signs of moderation, the Observatory will then consider issuing the (#3 Signal) ... tonight
18:46 The (#8 Signal) will remain in force before midnight tonight. When local winds show signs of moderation, the Observatory will consider issuing the (#3 Signal)
22:45 The (#8 Signal) will remain in force for a period of time. When local winds show signs of moderation, the Observatory will consider issuing the (#3 Signal)
October 10
01:47 The Observatory will consider issuing the (#3 Signal) ... before dawn
02:45 The Observatory will consider issuing the (#3 Signal) ... in the next hour or two
03:45 The Observatory will issue the (#3 Signal) soon
04:40 (The #3 Signal was issued)

Table - HKO's descriptions about the expected duration of the #8 Signal in its hourly tropical cyclone warning bulletins

獅子山為香港帶來的降雨打破十月單日雨量紀錄,而香港天文台期間所作的決定受到近年來最猛烈的爭議。

獅子山形成之前,廣東沿岸正受東北季候風影響。天文台於 10 月 6 日上午 3 時 35 分發出強烈季候風信號,提醒公眾本港或吹強東風。雖然該信號於早上取消,但於下午 11 時 40 分再度發出。7 日本港風勢頗大,離岸及高地吹強風,部分地方間中吹烈風。當天下午,一艘帆船於蒲台島一帶遇風浪翻轉 [新聞連結],其中一人被困於船底,其後被救出但送院搶救後不治,而另一人則受傷。

10 月 7 日下午,天文台表示獅子山將北移,並較預期更接近廣東沿岸,將於 8 日早上初時考慮發出三號強風信號,取代強烈季候風信號。

隨著獅子山的雨帶靠近香港,本地天氣於 10 月 8 日午夜左右轉差。天文台於 7 日下午 11 時 20 分發出黃色暴雨警告。自 8 日上午約 2 時起,當天大部分時間幾乎未有停雨。天文台於 8 日上午 4 時 40 分直接發出三號強風信號,當時獅子山位於香港西南偏南約 660 公里,而這是繼 2020 年熱帶氣旋森拉克以來再次跳過一號信號。

受獅子山及東北季候風的共同影響,風勢於 10 月 8 日早上仍然較為猛烈,長洲及青洲風力幾乎達烈風水平。加上持續大雨,當天上班上學市民情況狼狽。山泥傾瀉警告於上午 9 時 50 分發出,而半小時後新界北部水浸特別報告亦生效。一道較強的雨帶於上午約 11 時靠近本港,天文台於 11 時 20 分改發紅色暴雨警告,25 分鐘後更升至黑色。這是有紀錄以來第二次需要在 10 月發出此警告,對上一次為 5 年前受熱帶氣旋莎莉嘉影響時所發。在上午 10 時 45 分至 11 時 45 分的一小時間,灣仔、南區及東區分別錄得最高雨量達 86、84 及 76 毫米。

該道強雨帶掠過後,天文台於下午 12 時 45 分改發紅色暴雨警告;此警告共生效 5 小時,至下午 5 時 45 分被黃色暴雨警告取代,而此時本港已下了逾半天之久的豪雨終於有減弱的跡象。黃色暴雨警告及新界北部水浸特別報告同於下午 7 時 25 分取消。

在 10 月 8 日早上大雨及強風影響香港之時,於跑馬地樂活道的一幅大型棚架倒塌 [新聞連結],壓中兩架正駛經該處的車輛,司機受傷。在該處工作的 7 名工人失去聯絡,其後證實 5 人自行逃出,一男一女工人被救出,其中女工送院後不治。

香港大部分地區於 10 月 8 日錄得超過 200 至 300 毫米雨量。天文台當天雨量為 329.7 毫米,刷新 10 月單日雨量紀錄,同時為有紀錄以來第 8 高的日雨量,亦是自 1998 年 6 月 9 日以來的最高日雨量。

另一方面,10 月 8 日本港風勢大致平穩,天文台表示三號信號將於 8 日晚間至 9 日早上維持。可是,9 日凌晨開始風勢有所增強,昂坪持續風速達暴風水平,而長洲、大美督、塔門、大老山及橫瀾島吹烈風。數值模式亦顯示 9 日大部分時間風力仍然強勁。在幾乎沒有先兆之下,天文台於上午 4 時 40 分發出預警八號熱帶氣旋警告信號之特別報告,表示將最遲於上午 6 時 40 分改發八號信號。由於澳門早於上午 3 時已表示會改發八號風球,相信天文台或受該決定影響。

兩小時預警期過後,天文台改發八號東南烈風或暴風信號,當時獅子山於海南中部,位於香港西南約 560 公里。信號發出初時,天文台表示八號信號將於早上維持一段時間。諷刺的是,由於 10 月 9 日早上雨勢輕微,普遍市民覺得天氣並不較之前一天、三號信號生效時為差。在上午約 9 時,天文台稱將於下午初時考慮改發三號信號,但此後改發信號的時間被多次推遲 (見下面列表)。9 日日間風勢並沒有減弱,而隨著另一道雨帶靠近,下午天氣更轉趨惡劣。黃色暴雨警告於下午 1 時發出,部分地區此時錄得獅子山影響期間的最高風速,包括兩個參考站:赤鱲角錄得每小時 63 公里的烈風,而長洲錄得每小時 94 公里的暴風。至於位於高地的昂坪則曾錄得每小時 126 公里的颶風風速,陣風更達每小時 154 公里。

日落後不久,天文台表示八號信號將於午夜前維持。當晚流浮山、坪洲、九龍天星碼頭、大埔滘及塔門等地風勢較下午強。下午日間一直生效的黃色暴雨警告於晚上 9 時 05 分取消。10 月 9 日整體雨量較 8 日為低,但大多數地區仍然錄得過百毫米,天文台當天雨量為 130.3 毫米。

隨著獅子山於 10 月 9 日晚間開始西移,本港風勢終於在 10 日凌晨有所緩和。天文台表示將於日出前考慮改發三號強風信號,而該信號於上午 4 時 40 分發出,獅子山位於香港西南偏西約 610 公里。獅子山最接近香港時距離仍有 490 公里,成為自 1961 年以來令天文台發出八號信號的風暴中距港最遠的一個;而八號東南信號生效共 22 小時,是此方向的八號信號維持時間最長的一次,先前的紀錄為 1978 年熱帶氣旋愛娜斯的 21 小時 45 分鐘。但是,這與 1960 年熱帶氣旋瑪麗的 35 小時 35 分鐘單一信號紀錄 (東北方向) 還有一段距離。

獅子山的雨帶與風暴同步西移。10 月 10 日日出時份,本港的雨勢已只局限於西部;山泥傾瀉警告於上午 10 時取消。早上本港風勢繼續減弱,三號信號於下午 12 時 40 分被一號戒備信號取代。此信號生效時間較短,天文台於下午 2 時 20 分取消所有熱帶氣旋警告信號,當時獅子山已接近離開本港 800 公里範圍。10 日雨量明顯較 9 日少,但香港島大部分地區及大嶼山部分地區錄得超過 50 毫米雨量。

10 月 10 日天氣逐漸改善。由於乾燥的東北季候風於 11 日增強,本港當天大致天晴;而因熱帶氣旋圓規靠近,12 至 13 日天氣再度轉差。截至 10 日上午 4 時,政府共接獲 179 宗塌樹報告、6 宗水浸個案及 3 宗山泥傾瀉報告;風暴吹襲期間共有 14 人受傷並前往公立醫院急症室求診。

雖然獅子山距離香港較遠,而且已經登陸海南島,但仍然為本港帶來強風及大雨,情況較不尋常。事後天文台遭受抨擊,部分市民的觀點如下:

天文台助理台長宋文娟於一個記者會回答傳媒有關 10 月 8 日早上有否誤判形勢的問題時,表示極端天氣事件將變得更為頻密,呼籲大家加大力度減排減碳,此番言論亦備受抨擊。

為此,天文台台長鄭楚明於 10 月 11 日召開記者會,解釋當時所作的決定 [新聞連結:1 2 3 4]:

鄭楚明表示獅子山的狀況特別,是近數十年少見,並對有市民因惡劣天氣身故感到難過。至於就助理台長宋文娟於較早時的回應,鄭楚明認為當時是就該記者會的主題、即於 2050 年達致零碳排放而作出。

發佈時間 描述
10 月 9 日
06:49 預料八號烈風及暴風信號在今早維持一段時間
08:47 天文台會視乎風力情況在下午初時考慮改發三號強風信號
10:47 天文台會視乎風力情況在下午考慮改發三號強風信號
12:45 天文台會視乎本港風力情況在下午至黃昏考慮改發三號強風信號
13:45 天文台會視乎本港風力情況在黃昏前後考慮改發三號強風信號
15:45 待本港風力有緩和趨勢時,天文台會在今晚再考慮改發三號強風信號
18:46 八號烈風或暴風信號會在午夜前維持。當本港風力有跡象緩和時,天文台會考慮改發三號強風信號
22:45 八號烈風或暴風信號會維持一段時間。當本港風力有跡象緩和時,天文台會考慮改發三號強風信號
10 月 10 日
01:47 天文台會視乎本地的風力情況,在日出前考慮改發三號強風信號
02:45 天文台會視乎本地的風力情況,在未來一、兩小時考慮改發三號強風信號
03:45 天文台即將改發三號強風信號
04:40 (三號強風信號發出)

附表 - 香港天文台於其每小時熱帶氣旋警報中有關八號信號維持時間之描述

Image Gallery 圖片庫

Figure 1 - Numerical model forecasts: GFS (top left) and ECMWF (top right) ensemble forecasts before 92W crossed the Philippines; Deterministic forecasts on October 6 (bottom) [Source: Tropical Tidbits, weather.us, Typhoon2000.com]
圖 1 - 數值模式預報:92W 橫過菲律賓前之 GFS (左上) 及 ECMWF (右上) 模式集成預報圖;10 月 6 日之確定預報 (下) [來源:Tropical Tidbits, weather.us, Typhoon2000.com]

Figure 2 - Steering flow chart at 8 am October 7
圖 2 - 10 月 7 日上午 8 時之駛流場分佈圖

Figure 3 - 500 hPa weather map at 8 am October 7
圖 3 - 10 月 7 日上午 8 時之 500 百帕高空天氣圖

Figure 4 - Satellite image of LIONROCK at its formation
圖 4 - 獅子山形成時之衛星雲圖

Figure 5 - Forecast tracks from various official agencies at 8 am October 8
圖 5 - 10 月 8 日上午 8 時各官方氣象台之預測路徑

Figure 6 - Satellite image of LIONROCK at its peak intensity
圖 6 - 獅子山於巔峰強度時之衛星雲圖

Figure 7 - GFS forecast on October 7 of the 24-hour total precipitation for October 8
圖 7 - GFS 模式於 10 月 7 日預測 10 月 8 日的 24 小時總雨量圖

Figure 8 - Total rainfall at King's Park at 15-minute intervals on October 8 and 9
圖 8 - 10 月 8 及 9 日京士柏每 15 分鐘之總雨量圖

Figure 9 - Wind field analysis at 10:35 am October 7 (left) and 9:53 am October 9 (right)
圖 9 - 10 月 7 日上午 10 時 35 分 (左) 及 9 日上午 9 時 53 分 (右) 之風場掃描

Figure 10 - HKO's 9-day weather forecast on October 9, predicting storm force winds of up to force 11 to affect elevated locations
圖 10 - 10 月 9 日香港天文台之九天天氣預報,預料高地吹達 11 級的暴風

Figure 11 - ECMWF forecast indicating an area of gale force winds in the Pearl River Estuary in the afternoon of August 9
圖 11 - ECMWF 模式預測顯示 10 月 9 日下午珠江口有烈風區

Animation 12 - Radar images between October 8 and 10
動畫 12 - 10 月 8 至 10 日之雷達圖

Figure 13 - Local wind distribution maps at 4-hour intervals from midnight to 8 pm October 9
圖 13 - 10 月 9 日午夜至下午 8 時每 4 小時之本港風勢分布圖

Figure 14 - Wind speed time series at Chek Lap Kok, Cheung Chau, Ngong Ping, Kowloon Star Ferry Pier and Waglan Island (top to bottom) between October 8 and 10
圖 14 - 赤鱲角、長洲、昂坪、九龍天星碼頭及橫瀾島 (上至下) 於 10 月 8 至 10 日之風速時間序列圖

Figure 15 - Values of Δp(972) and Δp(S) between September 30 and October 10. Higher values indicate a larger pressure difference between Hong Kong and mainland China (Chenzhou for Δp(972) and Shanghai for Δp(S)).
圖 15 - 9 月 30 至 10 月 10 日間的 Δp(972) and Δp(S) 數值;較高數值表示香港與中國大陸 (Δp(972) 為郴州,Δp(S) 為上海) 的氣壓差距較大


Figure 16 - Rainfall distribution maps for October 7-10
圖 16 - 10 月 7 至 10 日之雨量分佈圖

Figure 17 - Collapsed scaffolding at Broadwood Road in Happy Valley on October 8 (Image from the Internet)
圖 17 - 10 月 8 日跑馬地樂活道棚架倒塌現場 (網上圖片)

Winds Recorded at Reference Stations 參考站所錄得的風速

The following table lists the maximum 10-minute average (sustained) wind speed recorded while tropical cyclone signals were in force. In some occasions, it is possible that the strongest winds were not recorded when the highest signal was in force.

下表列出各站於熱帶氣旋警告信號生效時所錄得的最高 10 分鐘平均 (持續) 風速,留意此風速不一定於最高信號生效期間錄得。

Station
風速站
Max. 10-min avg. wind speed
最高十分鐘平均風速
Beaufort classification
蒲福氏風級分類
Chek Lap Kok 赤鱲角 63 km/h GALE 烈風
Cheung Chau 長洲 94 km/h STORM 暴風
Kai Tak 啟德 46 km/h STRONG 強風
Lau Fau Shan 流浮山 44 km/h STRONG 強風
Sai Kung 西貢 56 km/h STRONG 強風
Sha Tin 沙田 33 km/h Fresh 清勁
Ta Kwu Ling 打鼓嶺 39 km/h Fresh 清勁
Tsing Yi (SHL) 青衣蜆殼油庫 33 km/h Fresh 清勁

Number of stations recording at least STRONG force (force 6 - 7) winds: 5
Number of stations recording at least GALE force (force 8 - 9) winds: 2
Number of stations recording at least STORM force (force 10 - 11) winds: 1
Number of stations recording HURRICANE force (force 12) winds: 0

錄得 強風 (6 - 7 級) 或更高風速的站數: 5
錄得 烈風 (8 - 9 級) 或更高風速的站數: 2
錄得 暴風 (10 - 11 級) 或更高風速的站數: 1
錄得 颶風 (12 級) 風速的站數: 0

Charts and Figures 各項數據

Table 1: Track data from HKWW:
表一 : 香港天氣觀測站之路徑資料

YYMMDDZZ Lat Long Wind
21100700 167N1116E 030
21100706 172N1116E 030
21100712 173N1114E 030
21100718 174N1110E 030
21100800 177N1108E 035
21100806 182N1107E 040
21100812 189N1107E 040
21100818 192N1101E 040
21100900 194N1099E 040
21100906 200N1099E 040
21100912 201N1098E 040
21100918 202N1090E 040
21101000 204N1082E 040
21101006 204N1071E 035
21101012 204N1062E 030

Table 2: Maximum gust and hourly average wind speed recorded in Hong Kong from HKO:
表二 : 香港天文台公佈的各站最高每小時平均風力和陣風數據 (英文)

Maximum Gust
Maximum Hourly Mean Wind
Direction
Speed (km/h)
Date/Month
Time
Direction
Speed (km/h)
Date/Month
Time
Central Pier ESE 95 9/10 17:33 ESE 44 9/10 18:00
Cheung Chau ESE 123 9/10 12:44 ESE 76 9/10 03:00
ESE 76 9/10 07:00
Cheung Chau Beach E 111 9/10 15:03 E 77 9/10 13:00
Green Island ENE 99 8/10 10:19 ENE 54 10/10 01:00
Hong Kong International Airport ESE 89 9/10 16:18 ESE 48 9/10 17:00
Kai Tak E 78 9/10 00:49 E 36 9/10 07:00
King's Park E 79 9/10 17:26 E 34 9/10 02:00
Lamma Island ESE 87 9/10 12:42 E 45 9/10 13:00
Lau Fau Shan E 69 9/10 22:10 E 36 9/10 23:00
Ngong Ping E 154 9/10 15:38 E 103 9/10 15:00
North Point ENE 82 8/10 10:15 E 49 10/10 01:00
Peng Chau SE 80 9/10 12:49 ESE 50 9/10 13:00
Ping Chau ENE 59 9/10 21:55 E 23 9/10 23:00
Sai Kung SE 81 8/10 13:17 ENE 46 10/10 00:00
Sha Lo Wan SE 102 9/10 16:24 E 39 9/10 03:00
SE 39 9/10 17:00
Sha Tin S 67 9/10 06:45 SSE 24 9/10 07:00
Star Ferry (Kowloon) ESE 85 9/10 13:02 E 45 9/10 07:00
E 45 9/10 21:00
Ta Kwu Ling E 71 9/10 18:07 E 27 9/10 09:00
Tai Mei Tuk E 99 9/10 12:55 E 62 9/10 14:00
Tai Mo Shan ESE 136 9/10 12:56 ESE 89 9/10 18:00
Tai Po Kau SE 82 9/10 06:55 E 46 10/10 00:00
Tate's Cairn SE 116 9/10 06:22 ESE 71 9/10 22:00
Tseung Kwan O E 75 9/10 13:01 SE 20 9/10 07:00
Tsing Yi Shell Oil Depot E 75 9/10 13:23 ESE 26 9/10 03:00
ESE 26 9/10 04:00
ESE 26 9/10 16:00
Tuen Mun Government Offices ESE 77 9/10 16:36 SE 24 9/10 08:00
Waglan Island ESE 101 9/10 15:29 E 74 10/10 01:00
Wetland Park ESE 59 9/10 14:38 E 18 9/10 23:00
Wong Chuk Hang E 89 9/10 08:19 E 30 9/10 02:00

Table 3: Rainfall (in millimetres) contributed by LIONROCK from HKO (figures in brackets are based on incomplete hourly data):
表三 : 香港天文台公佈的各站雨量資料 (英文) (方括號內之數據由不完整之每小時資料擷取)

07-Oct
08-Oct
09-Oct
10-Oct
Total Rainfall
(mm)
Hong Kong Observatory (HKO)
43.9
329.7
130.3
45.1
549.0
Hong Kong International Airport (HKA)
23.0
276.9
154.3
63.0
517.2
Cheung Chau (CCH)
[26.5]
160.5
92.0
76.0
[355.0]
H23 Aberdeen
43.5
269.0
163.5
49.0
525.0
N05 Fanling
21.5
238.0
101.0
16.0
376.5
N13 High Island
15.0
261.0
73.0
15.5
364.5
K04 Jordan Valley
27.5
417.0
117.5
36.0
598.0
N06 Kwai Chung
14.5
361.0
128.5
31.0
535.0
H12 Mid Levels
55.5
344.5
150.0
54.5
604.5
N09 Sha Tin
17.0
345.5
118.5
24.5
505.5
H19 Shau Kei Wan
66.5
369.0
133.0
48.0
616.5
SEK Shek Kong
[16.0]
274.5
130.5
29.0
[450.0]
K06 So Uk Estate
19.5
350.5
132.5
29.0
531.5
R31 Tai Mei Tuk
16.5
267.0
107.0
13.0
403.5
N17 Tung Chung
49.5
297.5
166.5
92.5
606.0
TMR Tuen Mun Reservoir
6.4
278.4
131.0
25.0
440.8

Last Accessed 最近訪問日期: Mon Apr 29 2024 23:11:41 HKT
Last Modified 最近修訂日期: Tue Sep 26 2023